In my init.el file I have this:
(global-set-key "\M-n" (lambda () (interactive) (insert "~")))
This allows me to use Alt-n on my Mac to produce the ~ character. It works fine in buffers etc. but when I try to use it in find-file I get
"End of history no default available".
C-h k reveals that M-n actually calls:
(lambda nil (interactive) (insert "~"))
Why doesn't this work with find-file?
Global key bindings are overridden by local (i.e., major-mode) key bindings, which are overridden by minor-mode bindings, which are overridden by... IOW, there are lots of levels of key binding.
In this case, your global binding is overridden by a minibuffer keymap binding.
In the minibuffer completion keymaps, which are local maps, M-n is bound to next-history-element. If you want M-n in such a map to be bound to something else, then you need to bind it. For example:
(define-key minibuffer-local-completion-map "\M-n" 'your-command)
There are several minibuffer completion keymaps, depending on your Emacs version. The two main ones are minibuffer-local-completion-map and minibuffer-local-must-match-map.
Related
Is there a way to advise a keymap or otherwise run a function after a keymap prefix, but before commands in the keymap?
Say I have a keymap with bindings for hideshow, but these bindings are only useful after hs-minor-mode is activated. How can I run (hs-minor-mode) after the prefix is entered, but before the functions in the map are called?
I thought making a prefix command and advising it might work, but that is an error (below).
Example:
(let ((map (define-prefix-command 'my-activate-fold 'my-fold-map)))
(define-key map "a" #'hs-hide-all)
(define-key map "s" #'hs-show-all)
(define-key map "l" #'hs-hide-level)
(global-set-key (kbd "<f6>") 'my-activate-fold))
;; error: wrong-type-argument commandp my-activate-fold
(define-advice my-activate-fold (:before (fn &rest r) "activate-hideshow")
(hs-minor-mode)
(apply fn r))
If I understand correctly, I think you may be approaching this incorrectly. For your specific question, no, there is no way to define a function which will run after a prefix key is called but before the command (an interactive function) which is bound to the key is run. However, I'm not sure that is really what your after. You can of course define commands which can wrap another command and do whatever you want. However, I'm not sure that is what you want either. You might want to state exactly what you want rather than part of what you believe is the solution to what you want.
Normal practice is for a minor mode to define a keymap and you add your mode specific key bindings to that map in a mode initialisation hook. In the case of hs-minor-mode, that is called hs-minor-mode-map. This map only exists inside buffers running hs-minro-mode and it takes precedence over the global map. So this is where you want to place your mode specific bindings. To do this, create a function which adds the bindings to the map and attach that to the hs-minor-mode-hook, which is run when hs-minor-mode is loaded.
(add-hook 'hs-minor-mode-hook (lambda ()
(define-key 'hs-minor-mode-map "a" #'hs-hide-all)
...))
The key bindings defined above will only exist if hs-minor-mode is active in the buffer. If it is not active, the keys used in the binding will either be bound to whatever the next highest map in the mode is or the global map or nothing (see the section on keymaps in the elsip manual for full details).
If what you want is to have specific hs-minor-mode bindings only exist in specific modes, then you can define those bindings in the keymap for that mode. For example, if you wanted hs-minor-mode bindings that only exist when you run hs-minor-mode in js2-mode, but not when you run hs-minor-mode in c-mode, then you can add the bindings to the js2-mode-map and load hs-minor-mode as part of the js2-mode-hook
If it is something else you are after, you need to clarify.
FWIW, you could simply advise the commands themselves:
(defun my-ensure-hs-minor-mode (&rest _args)
"Ensure `hs-minor-mode' is active."
(unless (bound-and-true-p hs-minor-mode)
(hs-minor-mode 1)))
(advice-add 'hs-hide-all :before #'my-ensure-hs-minor-mode)
(advice-add 'hs-show-all :before #'my-ensure-hs-minor-mode)
(advice-add 'hs-hide-level :before #'my-ensure-hs-minor-mode)
Your keymap then just works:
(require 'hideshow)
(let ((map (define-prefix-command 'my-activate-fold 'my-fold-map)))
(define-key map "a" #'hs-hide-all)
(define-key map "s" #'hs-show-all)
(define-key map "l" #'hs-hide-level))
(global-set-key (kbd "<f6>") 'my-activate-fold)
Im a new user in emacs, and use emacs because of the ansi-term/multi-term
Now I have to type ctrl+C twice to send it to term.
I would like to unbind the CTRL+C shortcut in emacs so I can send it directly to the term.
Is it possible?
Solution to override all other keymaps in term-mode buffers:
(defun jpk/term-mode-hook ()
(let ((map (make-sparse-keymap)))
(define-key map (kbd "C-c") 'term-send-raw)
(set-transient-map map (lambda () t))))
(add-to-hook 'term-mode-hook 'jpk/term-mode-hook)
Assuming you don't have any other binds to C-c (this is unlikely, see below):
(define-key term-mode-map (kbd "C-c") 'term-send-raw)
This was sufficient for me when starting emacs with emacs -q (i.e. without any of my customizations).
It is possible to change the key binding, but in my opinion it isn't worth it. C-c is a prefix key in Emacs, meaning that many key bindings start with it. You'll be fighting pervasive conventions and you will probably be frustrated. Accept that Emacs is not 100% a terminal emulator and there are a few minor compromises to be made.
Not too sure what you're asking, but binding a key to nil unbinds it.
So for a global C-c binding: (global-set-key "\C-c" nil).
And for a local binding in mode foo: (define-key foo-mode-map "\C-c" nil).
Note that you might need to undefine it in more than one local map. Remember too that you can use (current-local-map) and (current-global-map). For example, if you use M-x report-emacs-bug then C-c is a key prefix for multiple keys, in multiple keymaps. To undefine it in the bug-reporting buffer, you will need to use both of these:
(define-key (current-local-map) "\C-c" nil)
(define-key mml-mode-map "\C-c" nil)
How did I find out that mml-mode-map was involved? C-c C-h.
I wanted to change the behaviour of Ctrl-d key. So it will delete a word backward. I created a function:
(defun backward-delete-word (arg)
"Delete characters backward until encountering the beginning of a word.
With argument ARG, do this that many times."
(interactive "p")
(delete-region (point) (progn (backward-word arg) (point))))
Then inserted this into emacs.d:
(global-set-key (kbd "\C-d") 'backward-delete-word)
It works in fundamental-mode, but in php-mode it just removes the next character. When I click
Ctrl-h k Ctrl-d
Emacs gives this:
C-d runs the command c-electric-delete-forward, which is an
interactive compiled Lisp function in `cc-cmds.el'.
It is bound to C-d.
(c-electric-delete-forward ARG)
Somehow, it was reset to another function. How to find out, where it was reset and make it work with my function instead?
I don't have php-mode so I can't say for sure, but the binding is likely overriden in php-mode-map (which, as a major mode map, has higher precedence than the global map).
You can check by using C-h b to list all available key bindings and look for C-d or c-electric-delete-forward in the output buffer to see in which keymap the binding is defined.
Assuming php-mode-map overrides the C-d binding, you can disable it using
(define-key php-mode-map (kbd "C-d") nil)
When I load the python-mode.el file in emacs, I don't get any of the key bindings specified.
I started playing with the file and noticed that when I change:
(define-key map [(control c)(\#)] 'py-comment-region)
to:
(define-key global-map [(control c)(\#)] 'py-comment-region)
it works fine.
I went to look where the define the map variable and saw:
(defvar py-shell-map nil
"Keymap used in *Python* shell buffers.")
;; used by py-completion-at-point, the way of python.el
(defvar python-shell-map
(let ((map (copy-keymap comint-mode-map)))
(define-key map [tab] 'py-shell-complete)
(define-key map "\C-c-" 'py-up-exception)
(define-key map "\C-c=" 'py-down-exception)
map)
"Keymap used in *Python* shell buffers.")
Is the 'map' variable defined alright? Should I do some changes to my init file? I assume that this file works to everybody else, so why I need to change the 'map' variable to 'global-map' for it to work in my computer?
I'm running in a virtual machine if that's of any help.
The code you quoted in which you believe map is defined is not actually the relevant portion of the code. It is a different keymap used for a python shell, and it's not the one used when you edit a python file in Emacs.
The line you're editing appears in python-mode inside the following code block:
(defvar python-mode-map)
(setq python-mode-map
(let ((map (make-sparse-keymap)))
;; electric keys
(define-key map [(:)] 'py-electric-colon)
(define-key map [(\#)] 'py-electric-comment)
...
As you can see the variable map is first initialized as a "sparse keymap", then certain key-bindings get defined in that map, and finally the map is set as the value of python-mode-map. The latter is the keymap used in a buffer that is in python-mode.
So the keybindings should work - but of course only in a buffer that is in python-mode. To activate python-mode in a buffer, type M-x python-mode. This works only after the file python-mode.el has been loaded.
You can check if your current buffer is in python-mode in two ways:
your mode line should display the letters "Py"
type M-: ENTER major-mode ENTER -> this should print "python-mode" to the minibuffer
Each major mode and some minor modes have their own keymap, which is overlaid on the global keymap (which is global-map). When you press a key, Emacs tries to find a binding for that key in the overlaid keymaps, falling back to "more global" ones until it gets to the global-map. This is why global-map works and map doesn't.
In lisp, let is used to bind local variables. The map variable doesn't exist outside of the let (or maybe it does, but it's probably not the one you want). Read the documentation for let and defvar (e.g. C-h f defvar).
You need to figure out which keymap is being used in the major mode, and use define-key on that. In this case, (define-key python-mode-map (kbd "C-c #") 'py-comment-region) will probably work. N.B. I do not use python-mode.el, but looking at the source it seems like it uses python-mode-map as the keymap variable. The other keymaps are for auxiliary buffers.
Though I know how to set a global key-binding in Emacs, I find it hard to even Google out the code for a local (minor-mode specific) key-binding. For instance, I have this code in my .emacs:
;; PDFLaTeX from AucTeX
(global-set-key (kbd "C-c M-p")
(lambda ()
(interactive)
(shell-command (concat "pdflatex " buffer-file-name))))
I don't want to set it globally. Is there a function like local-set-key?
I use the following:
(add-hook 'LaTeX-mode-hook
(lambda () (local-set-key (kbd "C-0") #'run-latexmk)))
to have a bind defined for LaTeX mode alone.
To bind a key in a mode, you need to wait for the mode to be loaded before defining the key. One could require the mode, or use eval-after-load
(eval-after-load 'latex
'(define-key LaTeX-mode-map [(tab)] 'outline-cycle))
Don't forget either '—eval-after-load is not a macro, so it needs them.
You need to identify the key map for that mode (for example, LaTeX-mode-map) and use the function define-key. As an example, along with activating outline-minor-mode within LaTeX mode, I have:
(define-key LaTeX-mode-map [(tab)] 'outline-cycle))
In this case the major mode (LaTeX) holds the key binding, but there is also an outline-minor-mode-map.
None of the other answers satisfied my needs. So this may help other people. I wanted Tab to jump to the beginning of the line if I'm in Evil's normal mode (basically this means everywhere in Emacs), but I instead wanted it to cycle between org item states if I am in an org-mode document.
One option was to mess around with separate bindings and constant binding-rebinding whenever I switched buffers (because evil allows only one binding per key in its normal state).
But a more efficient option was to make Tab run my own code which runs the required function based on which major mode the current buffer uses. So if I am in a org buffer, this code runs org-cycle, and otherwise it runs evil-first-non-blank (go to the first non-whitespace character on the line).
The technique I used here can also be used by calling your custom function via global-set-key instead, for people who use regular non-evil Emacs.
For those who don't know Emacs lisp, the first line after the "if" statement is the true-action, and the line after that is the false-action. So if major-mode equals org-mode, we run org-cycle, otherwise we run evil-first-non-blank in all other modes:
(defun my/tab-jump-or-org-cycle ()
"jumps to beginning of line in all modes except org mode, where it cycles"
(interactive)
(if (equal major-mode 'org-mode)
(org-cycle)
(evil-first-non-blank))
)
(define-key evil-normal-state-map (kbd "<tab>") 'my/tab-jump-or-org-cycle)